Industrial truck



INDUSTRIAL TRUCK Filed Jan. 19, 1942 s sheets-sheet 1 GEO@ EVHNJHNEv May 23, 1944.. G. v. JoHNsoN INDUSTRIAL TRUCK Filed Jan. 19, 1942 3 Sheets-Sheet 2 WWW/W f up mul 3 Y UWA-AMER May 23, 1944. G. v. JOHNSON INDUSTRIAL TRUCK Filed Jan. 19; 1942 3 Sheets-Sheet S PRIOR ART aan n., ,23,1944 2,349,352

UNITED STATES PATENT 'ori-'ice Application sumti; 1942,' sedano. 421,341

16 Claims. (Cl. 214-113) This invention relates to industrial trucks, and more particularly to an improved load handling means for front end lift trucks.

Industrial trucks for handling loads in manuoperator against the danger from portions of the load falling from the elevated platform;

In accordance with the illustrated embodiment of the invention. an industrial truck is provided facturing plants, warehouses, and the like, genl having a normally vertically extending upright erally comprise a relatively short wheel-base veplvotally mounted adjacent the lower end therehicle having a power unit at one end and a load of to the truck frame and having a load hanhandling mechanism at the opposite end. The dling platform mounted for vertical movement load handling mechanism usually includes a genon the upright. A tilting mechanism is pivotally erally vertically extending upright, sometimes of l connected to the upper portion of the' upright. a telescopic type, and a load engaging platform and comprises a pair of arms WhicheXtend in a mounted on the upright for vertical movement generally horizontal relation rearwardly over the thereon. The upright is pivoted adjacent its .'Opei'atcfs Space On the truck to a Point therelower end onto the truck frame to enable the behind- AleVel mechanism is ldvotalllvr connectplatform to be tilted rearwardly for shifting the l ed to the ends of the arms for supporting such load rearwardly of the vehicle to effect a more arms in a spaced relation above 'the operators nearly uniform distribution of the weight on the space- Motor means mclinted 0n the frame are truck, and for enhancing the safety of the load connected to the levers for determining the anon the p1atf0rm, gular relation of the upright with respect to the For raising loads to relatively high elevations Vehicle frame and thus controlling the tilting and lowering them therefrom, the upright may movement thereof, as Well as acting as a Stabilizer be quite tall, or comprise a plurality of telescopic for the Upper end O f the Upright- The horizonmembers `for enabling the elevation of the load tal arms extending over the operators Space are supporting platform to a considerable height .provided with means extending therebetween above the vehicle frame. With the usual type of 26 forming a roof or a shield affording protection to lift truck a load in an elevated position upon the an operator stationed therein as against objects upright tends to sway considerably, due to exfalling from above, either from a storage pile ading, twisting or bending movements of the strucjacent which he may be working, or from the eletural members of the load handling mechanism. vated load platform. In industrial trucks commonly in use, a mecha- 3o It is, therefore, a general Object 0f the present nism for tilting the upright is attached to the invention to provide an industrial truck With a upright at a point adjacent its lower end, and new and improved load handling mechanism in such constructions the upright is unsupported whereby the upright iS effectively Stabilized dill'- from this` point upward against exing, twisting an elevated and loaded condition of the plating or swaying movements. Such swaying seriformously interferes with accurate manipulation of It is a further object of the invention to PIO- the load, and may cause parts of the load to be- Vide a neW and improved industrial truck arcome dislodged from the load supporting platrangement having a load handling mechanism form. mounted on one end thereof which includes a Furthermore, industrial trucks are usually pro- 40 load elevating platform and means providing Drovided with a space for an operator, which may tection to the truck operator from objects falling comprise a seat -or merely a standing platform, from above. 7 from which the truck is controlled. In manipu- A further object of the invention is to provide@ latng elevated loads, a portion or all of the load an industrial truck 0f the type described having may be a considerable distance above the operaa new and improved arrangement for stabilizing tor. Due to miscalculation or impaired overhead a load carried thereby in an elevated condition clearances a portion of the load onV the platform and alsc fOI' effecting atilting movement of the may be jarred and caused to fall therefrom. load handling mechanism. Merely while traveling along a driveway a sharp A further object of the invention is to provide obstruction may be struck with one of the wheels 5o in an industrial truck having a load handling of the vehicle, causing a jolt suiicient to dismechanism atone end thereof a new and im-V lodge a part of the load; or a sudden gust of proved arrangement for stabilizing such mechawind may flip a board, sheet of tin or the like, nism and effecting tilting movements thereof from a load of such material on the platform. while simultaneously affording protection to the Usually no protection is provided for the truck truck operator. i'

Further objects and advantages of the invention will appear from the following description. taken in connection with the accompanying drawings, while the features of novelty characterizing the invention will be pointed out with greater particularity in the appended claims.

In the drawings, Figure 1 is a side elevation illustrating an industrial truck constructed in accordance with one form of the invention; Figure 2 is a view in perspective, illustrating more clearly the structural arrangement of the operating mechanism of the invention; Figure 3 is a fragmentary view of one detail of the invention illustrating a modification thereof; Figure 4 is a perspective view of the upright structure mounted on one end of the truck and showing the power means for elevating the load engaging platform; Figure 5 is a side elevation of the upright structure showing in broken lines the direction of pull exerted by the lift chains; Figure Gis a perspective view of an upright structure such as may be mounted on the front end of a lift truck and which is explanatory of certain advantages of the invention; Figure 7 is a side elevation of the upright structure shown in Figure 6, showing in broken lines the direction of pull exerted by the lift chains; and Figure 8 is a sectional view taken on the line l-l of Figure 6.

Referring to the drawings, an industrial truck is showncomprising 'a main frame i0 suitably supported on sets of wheels Il and I2 and provided with a motor enclosed in the hood I3. The truck is provided with a load handling mechanism comprising a generally vertically extending upright structure I5, shown in this instance as being of the telescopic type, and which is mounted adjacent its lower end to one end of the truck frame I0 by a horizontal pivot indicated at I5. A load engaging member or platform, indicated generally at I1, and comprising outwardly extending arms I8 and an apron Il, is mounted for vertical movement upon the upright structure I5. iAn operator's compartment, indicated generally at 28, having a seat 2i and truck controls including a steering wheel 22, is provided on the vehicle frame III between the motor and the load handling mechanism.

'I'he upright structure I5 comprises a lower frame section 23 having a pair of vertically extending channel shaped uprights I4 within which is telescopically mounted an upper frame section 24 comprising a pair of uprights 28 tied together by a cross member 20.

Mounted between the uprights I4 is an hydraulic cylinder 35 from which projects a piston rod 40 carrying onits outer end the cross member 30 of the upper frame section 24. Fluid under pressure from the pump 4I is transmitted through a valve (not shown) to the line 49 and into the lower end of the lift cylinder 35 to eiect upward movement ofthe piston rod 40 to raise the cross member 30. A pair of lift chains 56 are anchored at one end to a cross member 51 secured to the upper ends of the uprights I4 and are trained over laterally spaced sprockets 58 journaled in brackets 59 depending from the cross member 30. At their opposite ends the chains 55 are connected to the load supporting platform I1. Rollers carried by the load supporting platform I1 are mounted for vertical movement within the channels of the uprights 28 of the upper frame section 24.

Elevation of the upper frame section 24 results in relative movement of the load supporting platform I1 with respect to the upright structure I5, the load supporting platform i1 being raised relative to the upper frame section 24 as the frame 75 section 24 is elevated with respect to the lower frame section 28.

It will be noted that the cross member 51 extends some distance to the rear of the uprights I4, being supported on the ends of angle members il suitably secured to the channel members I4. In rlllbdified structure as shown in Figure 5 the cross member 51 may be made in the form of a U with the ends thereof attached to the uprights I4 and the middle portion of the cross member spaced rearwardly from the rear surface of the uprights. The cross member 51 may be in the form of a channel so mounted on the uprights that the flanges 52 thereof extend rearwardly. Openings 63 are provided in the upper one of these flanges 52 for receiving and anchoring the ends of the chains 56.

When the upright structure I5 is completely telescoped, i. el, when the upper frame section 24 occupies its lowermost position, that portion of the chains 56 between the sprockets 58 and the cross member 51 extends rearwardly at nearly right angles to that portion ofthe chain between the sprockets 58 and the load supporting platform I1. As the upper frame section 24 is raised and the load carrying platform I1 is elevated, any tendency for the frame section 24 to sag forwardly under the load on the load supporting platform is counteracted by the rearward pull on the chains 55 which reacts through the sprockets 58 to maintain the verticality of the upper frame section 24.

The advantages of the construction illustrated in Figures 4 and 5 will better be understood by comparing the structures shown in Figures 4 and 5 with the structure shown in Figur 6 and 'I'. In Figures 6 and 7 is illustrated a construction heretofore employed in industrial trucks comprising an upright structure 1I having a load supporting platform 1I mounted thereon for vertical movement relative thereto., 'I'he upright structure 10 comprises a lower section 12 having a pair of vertically extending channel shaped uprights 1I, and an upper section 14 having a second pair of uprights 15 telescopically mounted in the uprights 18 and tied together at their upper ends by a cross member 15.

Mounted between the uprights 13 is an hydraulic cylinder 'I8 from which projects the piston rod 19 carrying a cross head 88 having laterally spaced sprockets 8| over which are trained lift chains 82, anchored at one end to the cross member at the lower end of the lower section 12, and which at their opposite ends are connected to the load supporting platform 1I. With this construction, raising of the cross head results in relative movement of the load supporting platform 1I with respect to the upright structure 10, and, as the cross head 88 is moved upwardly, the upper section 14 being moved conjointly therewith, the load supporting platform is raised relative thereto to its extreme upper position, at which the uprights 15 have moved out- .wardly of the uprights 13 and the load supporting platform has moved to the top of the upper frame section 14.

In prior art constructions that portion of the lift chains 82 between the sprockets 8| and the frame section 12 is disposed in the plane of the upright structure 10, and the stresses imparted by the load A on the laad suppOrting platform 1I tend to tip the upright structure in a forward direction. 'I'his tendency is proportionately increased as the load supporting platform is moved to extreme upper position. In these structures provision was made for stabilizing the upper frame section as it telescoped outwardly of the lower frame section of the upright bymeans of guide bars 'Il welded to the uprlghts 15 and by means of rollers 34 ilxed to the upper ends of the uprights 13 for engaging said bars.

In the new and improved structure embodying the present invention, that portion of the lift chains 55 between the sprockets Il and the frame section 23 extends rearwardly at an angle to the plane of the upright structure I and the stresses imposed by the load A on the load supporting platform I'I are counteracted by the stresses imposed in the opposite direction by the cross mem-- structures, is not required for providing stability to, the upper frame section in its extended position.

A combined stabilizing and tilting mechanism is provided for the upright structure I5 and which comprises a pair of arms 25 pivotally connected as at 25 to the upper portion of the upright I5. The

unl'isht is shown in the rearwardly tilted pesition and the platform I1 in a partially elevated position.

' In order to add rigidity to the load handling mechanism the tilting mechanism for the upright I5 is connected to the upper portion of the nrst section thereofv at a point abovel the operators compartment 2|, and the arms 2l are connected together by a plurality o! transverse braces 5I for preventing'relative movement therebetween. Similarly, the levers are connected together by a relatively heavy rod 52 secured between the extremities of the lever arms 3|. While it will be obvious that but one motor may be provided, if desired, for operating the levers 21-3I, two similar motors 34are provided, operating in unison, one connected to each of the lever arms 3| for convenience in mounting the vehicle motor. The levers 21-3I are made of relatively rugged proportions so as to be incapable of nexing, twisting or bending movements.

As shown more clearly in Figure 2, a sheet metal plate 53 is provided across the space between the arms 25 extending over the driver's compartment, forming a roof thereabove and afi fordingsubstantial protection to the operator arms 25 extend generally rearwardly in aparallel spaced relation over the operators space 20 and to a point therebehind. Extending upwardly from the opposite side members of the truck frame I0 are a pair of. levers 21, the upper ends of which are pivotally connected as at 29 to the corresponding ends of the arms 25 and support the arms 25 in a spaced relation above the operators space 2li. The levers 21 include portions 3| rigidly secured thereto by means of stub shafts 32 which are of stroke of the pistons 31 in the servo-motors 34. Operating fluidfor the servo-motors 34 is supplied from a reservoir 38 through conduit 39, motor `driven pump 4I, supply conduit. 42. and the control valve 43. The valve 43 maybe of. any suitablev type well known in the art, and may be connected through linkage 44 to an operating lever 45 which may be mounted adjacent the steering column in the operators compartment. By control of the valve 43 pressure iluid may be supplied selectively to corresponding opposite ends of the motors 34 through the conduits 46 and 4-1, while the exhaust fluid .may be returned through conduit 48 to the .':reservoir 38.

Bv controlling the energzation ofthe motors 34 the upright I5 of the load handling mechanism maybe 'caused to move to any desired angular position between its two limit positions. In broken Vlines in Figure l. the upright I5 is shown in the forward tilted positiont and with the platform I1 in the lowered position for picking up a load from the iloor. In full-flines, the

as regards objects which may tall toward him from above.

For manipulating loads with the load handling platform in elevated position, a solid sheet provided between the horizontal arms 25 might impair upward vision of the operator. It will be obvious that such a sheet could be substituted by a suitable screening in a manner indicated in Figure 3. For the same reason. an opening 54 may be provided in the rear of the sheet covering for the arms 25 permitting vvision to the -rear of the truck from the operators compartment. Y

Having described the principle of my invention in what is considered to be a preferred embodiment thereof, it is desired that it be understood that the specific details shown are merely illustrative, and that the invention may be carried out by other means.

I claim:

l. An industrial truck comprising a chassis. a normally vertically extending load supporting frame pivotally mounted on said chassis adjacent the lower end of said frame, a load supporting member mounted for vertical movement on said frame, an operators compartmenton said chassis. actuating means pivotally connected to said frame for effecting tilting movement thereof and including at least a portion extending over said operators compartment and downwardly behind the operator and providing protection foran operator therein from objects falling from-above, and controllable power means for driving said actuating mea-ns for determining the angular relation of said load supporting frame. and said chassis.

2. An industrial truck, a chassis. supporting wheels therefor. a normally vertically extending upright pivotally mounted onsaid chassis adiajacent one end of said chassis, a load supporting member mounted for vertical movement on said upright. an operators compartment on said chassis. actuating means for effecting tilting movement of said upright comprising means pivotally connected to the upper portion of said upright and extending rearwardly therefrom over said operators compartment and aording protection to an operator in said compartment from objects falling from above, and controllable pow.- er means for driving said actuating means.

3. An industrial trucbcomprising a frame, a normally vertically extending upright pivotally mounted adjacent one end of said frame, a load engaging member mounted for vertical movement on said upright, an operators compartment on said frame, means for eil'ecting tilting movement of said upright comprising a pair of spaced generally horizontal members connected to said upright adjacent the upper end thereof and extending rearwardly over said operators compartment, operating means connected to said horizontal members for cii'ectlng tilting movement of said upright. and means extending between said horizontal members forming a rooi' over said operators compartment. g

4. An industrial truck comprising a frame, a normally vertically extending upright horizontally pivoted on said truck frame adjacent one end thereof, a load engaging member mounted for vertical movement on said upright, an operators space on said frame, means forming a roof over said space and connected at the forward end to an upper portion of said upright, a pair of levers pivotally mounted on said frame to the rear of said space. said levers being pivotally connected at their upper ends to said roof forming means and supporting said means above said space, and motor means connected to said levers for effecting pivotal movement thereof and causing tilting of said upright.

5. An industrial truck comprising a frame, a generally vertically extending load handling mechanism pivotalhf mounted on an end of said frame, an operators space on said frame, a motor on said frame for operating said load handling mechanism, and means operatively connted at one end to said load handling mechanism and extending rearwardly over said space and forming substantially a roof thereabove, said means being connected to said motor on the opposite side of said space with respect to said load handling mechanism.

6. An industrial truck comprising a frame, an upright pivotally mounted adjacent the lower end thereof on one end of said frame, a load engaging member mounted for vertical movement on said upright, an operators space on said frame, means for stabilizing the upper end of said upright when said load engaging member is in a loaded and elevated condition, said stabilizing means comprising at least one arm pivotally connected to said upright adjacent the upper end thereof and extending rearwardly over said operators space, motor means mounted on said frame and operatively connected to the end of said arm opposite said upright for controlling the relative angular position of said upright.

7. An industrial truck comprising a frame, an upright pivotally mounted adjacent the lower end thereof on one end of said frame, a load engaging member mounted for vertical movement on said upright, an operators space on said frame, means for stabilizing the upper end of saidupright during the elevated and loaded condition of said load engaging member, said stabilizing means comprising at least one arm pivotally connected to the upper end of said upright and extending rearwardly over said operators space, a lever pivoted on sald frame, the upper end of said lever being pivotally connected to the end of said arm, motor means connected to said lever for determining the angular position of said upright relative to said frame, and means on said arm forming substantially a shield over said operators space.

8. An industrial truck comprising a frame, a normally vertically extending upright pivotally mounted on said frame, a load engaging member mounted for vertical movement on said upright, an operators space on said frame, means for tilting said upright comprising a cylinder and piston. rigid connecting means pivotally connected to said upright and to said piston and extending generally horizontally above said space.

9. An industrial truck comprising a frame, a

normally vertically extending upright pivotally mounted adjacent one end of said frame, a load engaging member mounted for vertical movement on said upright. an operators space on said frame. a rigid actuating member for tilting said upri'sht secured thereto and extending rearwardly over said space, means mounted on said frame for driving said actuating member, and means connecting said driving means and said member on the opposite side of said space with respect to said upright.

l0. An industrial truck comprising a frame, a normally vertically extending upright pivotally mounted on said frame adjacent one end thereof, a load engaging member mounted for vertical movement on said upright, an operators seat on said frame, a rigid member secured to said upright adjacent the upper end thereof and extending rearwardly therefrom in a spaced relation above said operators seat and to a point therebehind, and motor means mounted on said frame and operatively connected to said member behind said seat for effecting tilting movement or said upright.

l1. An industrial truck comprising a frame, a normally vertically extending upright pivotally mounted adjacent one end of said frame, a load engaging member mounted for vertical movement on said upright, an operators compartment on said frame, means for eilecting tilting of said upright including a pair of spaced arms pivotally connected adjacent the upper end of said upright and extending rearwardly in a generally parallel spaced relation above sani operators compartment and to a point therebehind, a pair -of lever arms pivotally mounted on said frame and extending upwardly therefrom, the upper ends of said lever arms being pivotally connected to the ends of corresponding of said first pair of arms, and motor means connected to said lever arms for eifecting tilting movement of said upright.

12. An industrial truck comprising a frame, a normally vertically extending uprightl guide frame mounted on a horizontal pivot adjacent one end of the truck frame, a load engaging member mounted for vertical movement on said upright, anV operators compartment on said frame, means forming a roof over said compartment connected to the upper portion of said upright and extending rearwardly therefrom to a point behind said compartment, an operating means on said frame and operatively connected to said roof forming means for effecting tilting movement of said upright.

13. An industrial truck comprising a frame. a normally vertically extending upright mounted on a horizontal pivot adjacent one end of said frame, a load engaging member mounted for vertical movement on said upright, an operators compartment on said frame, a pair of arms pivotally connected to an upper portion of said upright andextending rearwardly therefrom in a substantially parallel spaced relation above said compartment and to a point therebehind, a pair of levers pivoted intermediate their ends on said frame, the upper ends of said levers being pivotally connected to adjacent ends of corresponding of said arms, motor means mounted on said frame and'pivotally connected to the opposite ends of said levers, control means for said motor for effecting tilting of said upright thereby, and means extending between said arms forming a shield over said operators compartment and aording protection to the operator therein from objects falling from above.

14. An industrial truck comprising a chassis, a load supporting frame pivotally mounted on said chassis, an operators space on said chassis, a load engaging member mounted on said supporting frame for engagement under a load, actuating means mounted on said chassis for moving and holding said load supporting frame in a plurality of different angular positions with respect to said chassis, said actuating means being connected to said load supporting frame by rigid connecting means extending over said operators space and pivotally connected to said actuating means and to the upper end of said frame.

15. In an industrial truck, a chassis, a vertically extending upright mounted adjacent one end of said chassis, said upright comprising a frame pivotally mounted on said chassis, a second frame telescopically mounted in said rst frame, means for moving said second frame relative to said first frame comprising a cylinder and piston, said cylinder being mounted in said first frame, and said piston being directly connected to said second frame, a load engaging member mounted for vertical movement on one side of said upright, means for moving said load engaging member comprising a chain, one end of said chain being secured to said load engaging member, the opposite end of said chain being secured to said first frame at a point opposite said load engaging member and at a distance from the plane of said upright, a sprocket journaled adjacent the upper end of said second frame, said chain being trained over said sprocket.

16. In an industrial truck, a chassis, a vertically extending upright mounted adjacent one end of said chassis, said upright comprising a frame pivotally mounted on said chassis, a second frame telescopically mounted in said rst frame, means for moving said second frame relative to said rst frame, a load engaging member mounted for vertical movement on said upright, laterally spaced sprockets journaled adjacent the upper end of said second frame, means secured to said rst frame for securing a lift chain, said means being spaced from the side of said upright opposite the load engaging means, lift chains for moving said load 'engaging member, each said chain being' trained over respective ones of said sprockets and having one end attached to said member and the other end attached to said means.

GEORGE V. JOHNSON. 

